The invention relates in general to a synchronizing device that may have a synchronizer body, a sliding sleeve, a gearwheel with coupling toothing and a synchronizer ring that is displaceable between synchronizer body and coupling toothing axially in and counter to the synchronization direction.
One problem in a synchronizing device of this type is that, when the sliding sleeve is returned from a shift position, in which the gearwheel is connected to the synchronizer body via the coupling toothing in an effective manner in terms of transmission, into a neutral position, in which the gearwheel is released from the synchronizer body, the synchronizer ring is frequently not returned precisely into this neutral position, but is still in frictional contact with the gearwheel. This may cause jolting or wobbling of the synchronizer body and/or of a cone system between synchronizer ring and gearwheel, which is associated with a corresponding production of noise which irritates the user. Likewise with a production of noise, this may be associated with a frequently asymmetrical loading of a bearing which is generally designed as a needle bearing and may cause shrieking of the needle bearing.
For example, in a synchronizing device of the type in question according to DE 35 36 361 A1 and DE 94 08 943 U, a radially spring-mounted latching element which is guided on the synchronizer body and is in the form of a cylindrical roller or a ball is provided. In the neutral position, the latching element is intended to engage in a receptacle which is provided centrally on the sliding sleeve and has radial slopes, as a result of which, in the neutral position, the latching element is positionally fixed centrally and radially on the inside on the sliding sleeve, but a precise radial alignment of the spring force does not have to be set and therefore a tilting moment can engage on the synchronizer ring causing tilting of same. It is therefore not possible for the synchronizer ring to be fully released from the shift wheel at the cones thereof, that is to say, it is not possible for a complete air gap to be formed between the cones, and force continues to be undesirably transmitted between the cones. The synchronizer ring can therefore not be brought reliably into the neutral position as specified.
EP 1 624 212 A1 proposes an equalizing lever, pivotable about a central axis for displacing the synchronizer ring against the blocking toothing, wherein the equalizing lever, arranged between two synchronizing devices arranged mirror-symmetrically with respect to each other, acts on the two synchronizer rings of the synchronizing devices.
According to DE 195 80 558 C1, the spring mounting of the latching element is released in a receptacle which is supported movably on the two synchronizer rings of the synchronizing devices arranged mirror-symmetrically with respect to each other, in order to counteract a tilting of the synchronizer rings.
In DE 10 2009 039 934 A1, on the path into the neutral position, the spring-mounted latching element, for the alignment thereof, is guided on radially conical, converging guide surfaces into the receptacle provided centrally on the sliding sleeve.